Multilayer ceramic capacitor

ABSTRACT

In a multilayer ceramic capacitor, an interposer includes, on a side of a first external electrode in a length direction, a first through hole that penetrates the interposer in a stacking direction, and provides electrical conduction between a first joining electrode and a first mounting electrode. The first through hole further includes a first metal film provided on an inner wall thereof. The interposer includes, on a side of a second external electrode in the length direction, a second through hole that penetrates the interposer in the stacking direction, and provides electrical conduction between a second joining electrode and a second mounting electrode. The second through hole further includes a second metal film provided on an inner wall thereof. A first uncovered portion is provided, which is not covered by the first metal film, on a first surface of the inner wall of the first through hole, and a second uncovered portion is provided which is not covered by a second metal film on the first surface of the inner wall of the second through hole.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to Japanese PatentApplication No. 2020-077297 filed on Apr. 24, 2020. The entire contentsof this application are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a multilayer ceramic capacitor.

2. Description of the Related Art

Recently, a large-capacitance and small-size multilayer ceramiccapacitor has been demanded. Such a multilayer ceramic capacitorincludes an inner layer portion in which dielectric layers made of aferroelectric material having relatively high dielectric constant andinternal electrodes are alternately stacked. Furthermore, dielectriclayers as outer layer portions are provided on and below the inner layerportion, thus forming a rectangular multilayer main body. Side gapportions are provided on both side surfaces of the multilayer main bodyin the width direction, thus forming a multilayer body. Externalelectrodes are provided on both end surfaces of the multilayer body inthe longitudinal direction, thus forming a capacitor main body.

Furthermore, in order to suppress the generation of so-called “acousticnoise”, a multilayer ceramic capacitor is known which includes aninterposer provided on the side of the capacitor main body on which asubstrate is mounted.

In the interposer, a through hole is sometimes provided which provideselectrical conduction between the external electrodes and the substrate.Furthermore, solder is used for joining a capacitor main body and theinterposer. When the solder flows in this through hole, the through holeis filled with the solder. Meanwhile, the solder is also used whenmounting the multilayer ceramic capacitor to the substrate. At thistime, if the through hole is filled with the solder, the solder formounting cannot flow in the through hole, and thus the posture at thetime of mounting is not stable.

For this reason, prior art has been known which covers an upper portionof a through hole with a solder-non-adhering film, thus preventingsolder from flowing in the through hole when joining a capacitor mainbody and an interposer and preventing the through hole from being filledwith the solder (refer to Japanese Unexamined Patent Application,Publication No. 2015-23209).

SUMMARY OF THE INVENTION

However, according to the above prior art, it is necessary to furtherperform a step of covering the upper portion of the through hole with asolder non-adhering film.

Preferred embodiments of the present invention provide multilayerceramic capacitors each capable of stabilizing a posture upon mountingby providing a gap more easily in a through hole in an interposer.

A preferred embodiment of the present invention provides a multilayerceramic capacitor including a capacitor main body; and an interposer,the capacitor main body including a multilayer body including dielectriclayers and internal electrode layers alternately stacked, a first mainsurface on one side and a second main surface on the other side in astacking direction, and a first end surface on one side and a second endsurface on the other side in a length direction intersecting thestacking direction, a first external electrode provided on the first endsurface of the multilayer body and extending from the first end surfaceto a portion of the first main surface and a portion of the second mainsurface, and a second external electrode provided on the second endsurface of the multilayer body and extending from the second end surfaceto a portion of the first main surface and a portion of the second mainsurface, the interposer being provided at or adjacent to the second mainsurface of the capacitor main body, and including a first surface facingthe second main surface, and a second surface opposite to the firstsurface, in which the interposer includes, on a side of the firstexternal electrode in the length direction, a first joining electrode onthe first surface, a first mounting electrode on the second surface, anda first through hole that penetrates the interposer in the stackingdirection, and provides electrical conduction between the first joiningelectrode and the first mounting electrode, the first through holefurther including a first metal film provided on an inner wall thereof,and includes, on a side of the second external electrode in the lengthdirection, a second joining electrode on the first surface, a secondmounting electrode on the second surface, a second through hole thatpenetrates the interposer in the stacking direction, and provideselectrical conduction between the second joining electrode and thesecond mounting electrode, the second through hole further including asecond metal film provided on an inner wall thereof, a first uncoveredportion is provided, which is not covered by the first metal film, onthe first surface of the inner wall of the first through hole, and asecond uncovered portion is provided which is not covered by the secondmetal film on the first surface of the inner wall of the second throughhole.

According to preferred embodiments of the present invention, it ispossible to provide multilayer ceramic capacitors each capable ofstabilizing posture upon mounting by providing a gap more easily in athrough hole in an interposer.

The above and other elements, features, steps, characteristics andadvantages of the present invention will become more apparent from thefollowing detailed description of the preferred embodiments withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a state in which a multilayerceramic capacitor of a first preferred embodiment of the presentinvention is mounted on a substrate.

FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1 ofthe multilayer ceramic capacitor of the first preferred embodiment ofthe present invention.

FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1of the multilayer ceramic capacitor of the first preferred embodiment ofthe present invention.

FIG. 4 is a schematic perspective view of a multilayer body of themultilayer ceramic capacitor of the first preferred embodiment of thepresent invention.

FIG. 5 is a schematic perspective view of a multilayer main body of themultilayer ceramic capacitor of the first preferred embodiment of thepresent invention.

FIGS. 6A to 6C provide enlarged views of a portion of the multilayerceramic capacitor surrounded by a circle shown in FIG. 2 in the firstpreferred embodiment in which FIG. 6A illustrates the first preferredembodiment, and FIGS. 6B and 6C illustrate modifications of the firstpreferred embodiment of the present invention.

FIG. 7 is a flowchart for explaining a method of manufacturing themultilayer ceramic capacitor.

FIG. 8 is a schematic plan view of a material sheet.

FIG. 9 is a schematic view showing a stacked state of material sheets.

FIG. 10 is a schematic perspective view of a mother block.

FIGS. 11A and 11B provide partially enlarged views of a multilayerceramic capacitor in a second preferred embodiment of the presentinvention in which FIG. 11A is one portion in the length direction, andFIG. 11B is the other portion in the length direction.

FIGS. 12A and 12B provide partially enlarged views of the multilayerceramic capacitor in a modification of the second preferred embodimentof the present invention in which FIG. 12A is one portion in the lengthdirection, and FIG. 12B is the other portion in the length direction.

FIG. 13 is a view of the multilayer ceramic capacitor of themodification of the second preferred embodiment of the present inventionseen from a side of the second surface.

FIGS. 14A and 14B provide partially enlarged views of a state in which amultilayer ceramic capacitor of a third preferred embodiment of thepresent invention is mounted on a substrate in which FIG. 14A is oneportion in the length direction, and FIG. 14B is the other portion inthe length direction.

FIGS. 15A and 15B provide partially enlarged views of a multilayerceramic capacitor of a fourth preferred embodiment of the presentinvention in which FIG. 15A is one portion in the length direction, andFIG. 15B is the other portion in the length direction.

FIGS. 16A and 16B provide partially enlarged views of a multilayerceramic capacitor of a fifth preferred embodiment of the presentinvention in which FIG. 16A is one portion in the length direction, andFIG. 16B is the other portion in the length direction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First PreferredEmbodiment

First, a multilayer ceramic capacitor 1 according to a first preferredembodiment of the present invention will be described.

FIG. 1 is a schematic perspective view of a state in which themultilayer ceramic capacitor 1 of the first preferred embodiment ismounted on a substrate 200. FIG. 2 is a cross-sectional view taken alongthe line II-II in FIG. 1 of the multilayer ceramic capacitor 1 of thefirst preferred embodiment. FIG. 3 is a cross-sectional view taken alongthe line III-III in FIG. 1 of the multilayer ceramic capacitor 1 of thefirst preferred embodiment.

The multilayer ceramic capacitor 1 has a substantially rectangularshape, and includes a capacitor main body 1A including a multilayer body2 and a pair of external electrodes 3 provided at both ends of themultilayer body 2, and an interposer 4 affixed to the capacitor mainbody 1A. Furthermore, the multilayer body 2 includes an inner layerportion 11 including a plurality of sets of a dielectric layer 14 and aninternal electrode layer 15.

In the following description, as a term representing the orientation ofthe multilayer ceramic capacitor 1, the direction in which the pair ofexternal electrodes 3 are provided in the multilayer ceramic capacitor 1is defined as the length direction L. The direction in which thedielectric layers 14 and the internal electrode layers 15 are stacked(or laminated) is defined as the stacking direction T. The directionintersecting both the length direction L and the stacking direction T isdefined as the width direction W. It should be noted that, in thepreferred embodiments, the width direction W is orthogonal to both ofthe length direction L and the stacking direction T.

FIG. 4 is a schematic perspective view of the multilayer body 2. Themultilayer body 2 includes a multilayer main body 10, and a side gapportion 30. FIG. 5 is a schematic perspective view of the multilayermain body 10.

In the following description, among the six outer surfaces of themultilayer body 2 shown in FIG. 4, a pair of outer surfaces on oppositesides in the stacking direction T are respectively defined as a firstmain surface Aa and a second main surface Ab, a pair of outer surfaceson opposite sides in the width direction W are respectively defined as afirst side surface Ba and a second side surface Bb, and a pair of outersurfaces on opposite sides in the length direction L are respectivelydefined as a first end surface Ca and a second end surface Cb.

It should be noted that, in a case in which it is not necessary tospecifically distinguish the first main surface Aa and the second mainsurface Ab from each other, they will be collectively described as themain surface A, in a case in which it is not necessary to specificallydistinguish the first side surface Ba and the second side surface Bbfrom each other, they will be collectively described as the side surfaceB, and in a case in which it is not necessary to specificallydistinguish the first end surface Ca and the second end surface Cb fromeach other, they will be collectively described as the end surface C.

The multilayer body 2 is preferably rounded at a corner R1 and a ridgeR2. The corner R1 is a portion where the main surface A, the sidesurface B, and the end surface C intersect. The ridge R2 is a portionwhere two surfaces of the multilayer body 2, i.e., the main surface Aand the side surface B, the main surface A and the end surface C, or theside surface B and the end surface C intersect.

In addition, surface irregularities and the like may be formed on aportion or all of the main surface A, the side surface B, and the endsurface C of the multilayer body 2. The dimension of the multilayer body2 is not particularly limited; however, it is preferable that thedimension in the length direction L is about 0.2 mm or more and about 10mm or less, the dimension in the width direction W is about 0.1 mm ormore and about 10 mm or less, and the dimension in the stackingdirection T is about 0.1 mm or more and about 5 mm or less, for example.

As shown in FIG. 5, the multilayer main body 10 includes the inner layerportion 11, an upper outer layer portion 12 a disposed at or adjacent tothe first main surface Aa of the inner layer portion 11, and a lowerouter layer portion 12 b disposed at or adjacent to the second mainsurface Ab of the inner layer portion 11.

The inner layer portion 11 includes the plurality of sets of dielectriclayer 14 and the internal electrode layer 15 which are alternatelystacked along the stacking direction T.

The dielectric layer 14 has a thickness of about 0.5 μm or less. Thedielectric layer 14 is made of a ceramic material. As the ceramicmaterial, for example, a dielectric ceramic including BaTiO₃ as a maincomponent is used. Furthermore, a ceramic material obtained by adding atleast one of sub-components such as Mn compounds, Fe compounds, Crcompounds, Co compounds, and Ni compounds to these main components maybe used. It should be noted that the number of dielectric layers 14including the multilayer main body 10 including the upper outer layerportion 12 a and the lower outer layer portion 12 b is preferablyfifteen sheets or more and 700 sheets or less.

The internal electrode layer 15 includes a plurality of first internalelectrode layers 15 a and a plurality of second internal electrodelayers 15 b. The first internal electrode layers 15 a and the secondinternal electrode layers 15 b are alternately arranged. It should benoted that, when it is not necessary to distinguish the first internalelectrode layer 15 a from the second internal electrode layer 15 b, theywill be collectively described as the internal electrode layer 15.

The first internal electrode layer 15 a includes a first opposingportion 152 a provided opposite to the second internal electrode layer15 b, and a first lead-out portion 151 a extending from the firstopposing portion 152 a to the side of the first end surface Ca. An endof the first lead-out portion 151 a is exposed on the first end surfaceCa and is electrically connected to a first external electrode 3 a to bedescribed later.

The second internal electrode layer 15 b includes a second opposingportion 152 b provided opposite to the first internal electrode layer 15a, and a second lead-out portion 151 b extending from the secondopposing portion 152 b to the second end surface Cb. An end of thesecond lead-out portion 151 b is electrically connected to a secondexternal electrode 3 b to be described later.

Charge is accumulated in the first opposing portion 152 a of the firstinternal electrode layer 15 a and the second opposing portion 152 b ofthe second internal electrode layer 15 b, such that the characteristicsof the capacitor are developed.

The internal electrode layer 15 is preferably made of a metallicmaterial such as Ni, Cu, Ag, Pd, or Au, or Ag—Pd alloy, for example. Thethickness of the internal electrode layer 15 is preferably about 0.5 μmor more and about 2.0 μm, for example. The number of the internalelectrode layers 15 is preferably fifteen or more and 200 or less intotal of the first internal electrode layer 15 a and the second internalelectrode layer 15 b.

The outer layer portion 12 is made of the same material as thedielectric layer 14 of the inner layer portion 11. Furthermore, thethickness of the outer layer portion 12 is, for example, about 20 μm orless, and preferably about 10 μm or less.

The side gap portion 30 includes a first side gap portion 30 a providedat or adjacent to the first side surface Ba of the multilayer main body10 and a second side gap portion 30 b provided at or adjacent to thesecond side surface Bb of the multilayer main body 10.

It should be noted that, in a case in which it is not necessary tospecifically distinguish the first side gap portion 30 a and the secondside gap portion 30 b from each other, they will be collectivelydescribed as the side gap portion 30.

The side gap portion 30 covers the end on the side in the widthdirection W of the internal electrode layer 15 which is exposed on bothsides of the multilayer main body 10 along its end. The side gap portion30 is made of the same material as the dielectric layer 14, and furtherincludes Mg as a sintering aid. Mg migrates to the side of the internalelectrode layer 15 side during sintering of the side gap portion 30,such that Mg is segregated on the side of the side gap portion 30 incontact with the internal electrode layer 15. Furthermore, an interfaceis present between the multilayer main body 10 and the side gap portion30.

The thickness of the side gap portion 30 is, for example, about 20 μm orless, and preferably about 10 μm or less.

Furthermore, although the side gap portion 30 is a single layer in thepresent preferred embodiment, the present invention is not limitedthereto, and the side gap portion 30 may have a two-layer structure ofan outer side gap layer located on the outside and an inner side gaplayer located on the side of the internal electrode layer 15.

In this case, it is preferable that the content of Si in the outer sidegap layer be larger than that in the inner side gap layer. With such aconfiguration, it is possible to improve the strength of the side gapportion 30, thus improving the bending strength of the multilayerceramic capacitor 1. Furthermore, since cracks or chipping hardly occurin the side gap portion 30 and thus it is possible to prevent theintrusion of moisture, it is possible to ensure the insulating propertyof the multilayer ceramic capacitor 1. As a result, it is possible toprovide the multilayer ceramic capacitor 1 with improved reliability.Furthermore, the interface is present between the outer side gap layerand the inner side gap layer. This interface makes it possible toalleviate the stress acting on the multilayer ceramic capacitor 1.

The external electrode 3 includes a first external electrode 3 aprovided on the first end surface Ca of the multilayer body 2, and asecond external electrode 3 b provided on the second end surface Cb ofthe multilayer body 2. It should be noted that, in a case in which it isnot necessary to specifically distinguish between the first externalelectrode 3 a and the second external electrode 3 b, they will becollectively described as an external electrode 3. The externalelectrode 3 covers not only the end surface C, but also a portion ofeach of the main surface A and the side surface B at or adjacent to theend surface C.

As described above, the end of the first lead-out portion 151 a of thefirst internal electrode layer 15 a is exposed at the first end surfaceCa and electrically connected to the first external electrode 3 a.Furthermore, the end of the second lead-out portion 151 b of the secondinternal electrode layer 15 b is exposed to the second end surface Cb,and is electrically connected to the second external electrode 3 b. Thisprovides a structure in which a plurality of capacitor elements areelectrically connected in parallel between the first external electrode3 a and the second external electrode 3 b.

Furthermore, as shown in FIG. 2, the external electrode includes athree-layer structure including a foundation electrode layer 31, aconductive resin layer 32 provided on the foundation electrode layer 31,and a plated layer 33 provided on the conductive resin layer 32.

It should be noted that the external electrodes 3 include a three-layerstructure in the present preferred embodiment; however, the presentinvention is not limited thereto, and may include a two-layer structureor the like, other than the three-layer structure, for example.

The foundation electrode layer 31 is provided, for example, by applyingand firing a conductive paste including a conductive metal and glass. Asthe conductive metal of the foundation electrode layer 31, for example,Cu, Ni, Ag, Pd, Ag—Pd alloy, Au or the like can be used.

The conductive resin layer 32 is provided so as to cover the foundationelectrode layer 31. The conductive resin layer 32 has any configurationincluding a thermosetting resin and a metal component. As specificexamples of the thermosetting resin, various known thermosetting resinssuch as epoxy resin, phenolic resin, urethane resin, silicone resin,polyimide resin, and the like can be used. As the metal component, forexample, Ag or a metal powder coated with Ag on the surface of the basemetal powder can be used.

The plated layer 33 preferably includes plating of one metal or an alloyincluding the metal selected from the group consisting of, for example,Cu, Ni, Su, Ag, Pd, Ag—Pd alloy, Au, or the like.

Thus, since the conductive resin layer 32 includes a thermosettingresin, for example, the conductive resin layer 32 is more flexible thanthe foundation electrode layer 31 made of a plated film or a firedproduct of a conductive paste. Therefore, even when an impact caused byphysical shock or thermal cycling to the multilayer ceramic capacitor 1is applied, the conductive resin layer 32 defines and functions as abuffer layer, such that the generation of cracks in the multilayerceramic capacitor 1 is prevented, piezoelectric vibration is easilyabsorbed, and an effect of reducing or preventing the “acoustic noise”is exhibited.

FIGS. 6A to 6C provide enlarged views of the multilayer ceramiccapacitor 1 surrounded by a circle shown in FIG. 2 in the firstpreferred embodiment in which FIG. 6A illustrates the first preferredembodiment, and FIGS. 6B and 6C illustrate modifications of the firstpreferred embodiment. It should be noted that FIGS. 6A to 6C areenlarged views on the left side of FIG. 2, which is one portion on theleft side in the length direction L. Since the configuration on theright side of FIG. 2, which is one portion on the right side in thelength direction L, is substantially the same as the portion on the leftside except for its symmetry, they are only shown in FIG. 2.

The interposer 4 includes a plate-shaped interposer main body 40. Theinterposer main body 40 is made of a single plate including insulatingresin as a main material component. The interposer main body 40 is in asubstantially rectangular shape having substantially the same size asthe capacitor main body 1A in a plan view.

The interposer main body 40 is provided on the side of the second mainsurface Ab of the capacitor main body 1A, and includes a first surface 4a facing the second main surface Ab, and a second surface 4 b oppositeto the first surface 4 a. As shown in FIGS. 1, 2, 3, and 6, whenassuming that the side of the first main surface Aa in the stackingdirection T is an upper side and the side of the second main surface Abis a lower side, the first surface 4 a as the upper surface is locatedon the side of the second main surface Ab of the capacitor main body,and the second surface 4 b as the lower surface is affixed to thesubstrate 200 on which the multilayer ceramic capacitor 1 is mounted.

A first joining electrode 41 a is provided on the first surface 4 a onthe side of the first external electrode 3 a in the length direction Lof the interposer main body 40. A first mounting electrode 42 a isprovided on the side of the second surface 4 b of the interposer mainbody 40. A first through conductive portion 43 a is provided whichpenetrates the interposer main body 40 in the stacking direction T andprovides electric conduction between the first joining electrode 41 aand the first mounting electrode 42 a. Furthermore, the first externalelectrode 3 a and the first joining electrode 41 a are joined with eachother in an electrically conductive manner by a first electricallyconductive joining agent 44 a which is, for example, solder for joining.

A second joining electrode 41 b is provided on the first surface 4 a onthe side of the second external electrode 3 b in the length direction Lof the interposer main body 40. A second mounting electrode 42 b isprovided on the side of the second surface of the interposer main body40. A second through conductive portion 43 b is provided whichpenetrates the interposer main body 40 in the stacking direction T andprovides electric conduction between the second joining electrode andthe second mounting electrode 42 b. Furthermore, the second externalelectrode 3 b and the second joining electrode 41 b are joined with eachother in an electrically conductive manner by a second electricallyconductive joining agent 44 b which is, for example, solder for joining.

Here, a first joining region 45 a shown in FIGS. 6A to 6C is a joiningregion between the first external electrode 3 a and the first conductivejoining agent 44 a. The first joining region 45 a extends directly abovean end Pa of the first through conductive portion 43 a on the side ofthe first surface 4 a.

A second joining region 45 b is a joining region between the secondexternal electrode 3 b and the second conductive joining agent 44 b. Thesecond joining region 45 b extends directly above an end of the secondthrough conductive portion 43 b on the side of the second surface 4 b.

It should be noted that the first joining region 45 a refers to a regionin which the first external electrode 3 a and the first conductivejoining agent 44 a are in close contact with each other and electricallyconnected to each other, and no space is provided therebetween.

The second joining region 45 b refers to a region in which the secondexternal electrode 3 b and the second conductive joining agent 44 b arein close contact with each other and electrically connected to eachother, and no space is provided therebetween.

The first through conductive portion 43 a includes a first metal filmprovided on the inner wall of a first through hole 46 a penetrating theinterposer main body 40 in the stacking direction T. In the presentpreferred embodiment, the first metal film covers the entire surface ofthe inner wall of the first through hole 46 a.

The second through conductive portion 43 b includes a second metal filmprovided on the inner wall of a second through hole 46 b penetrating theinterposer main body 40 in the stacking direction T. In the presentpreferred embodiment, the second metal film covers the entire surface ofthe inner wall of the second through hole 46 b.

In the first preferred embodiment, the first joining region 45 a is ajoining region between the first external electrode 3 a and the firstconductive joining agent 44 a. The first joining region 45 a extendsdirectly above the end Pa at the upper end of the first throughconductive portion 43 a on the side of the first external electrode 3 a,and further extends beyond the first through hole 46 a and over theentire region directly above the first through hole 46 a.

The second joining region 45 b is a joining region between the secondexternal electrode 3 b and the second conductive joining agent 44 b. Thesecond joining region 45 b extends directly above the end Pb at theupper end of the second through conductive portion 43 b on the side ofthe second external electrode 3 b, and further extends beyond the secondthrough hole 46 b and over the entire region directly above the secondthrough hole 46 b.

However, the present invention is not limited thereto. As shown in FIG.6B, the first joining region 45 a may cover not the entire regiondirectly above the first through hole 46 a, but only a portion thereof.The second joining region 45 b may cover not the entire region directlyabove the second through hole 46 b, but only a portion thereof.

It should be noted that, in the first preferred embodiment, as shown inFIG. 6A, the first conductive joining agent 44 a, which is solder forjoining, does not flow in the interior of the first through hole 46 a,and the first metal film provided on the inner wall of the first throughhole 46 a defines and functions as the first through conductive portion43 a.

The second conductive joining agent 44 b, which is solder for joining,does not flow in the interior of the second through hole 46 b, and thesecond metal film provided on the inner wall of the second through hole46 b defines and functions as the second through conductive portion 43b.

However, the present invention is not limited thereto, and as shown inFIG. 6C, the first conductive joining agent 44 a, which is solder forjoining, may flow in the interior of the first through hole 46 a, andthus, the first metal film provided on the inner wall of the firstthrough hole 46 a and the first conductive joining agent 44 a which hasflowed in may define and function as the first through conductiveportion 43 a.

Furthermore, the second conductive joining agent 44 b, which is solder,may flow in the interior of the second through hole 46 b, and thus, thesecond metal film provided on the inner wall of the second through hole46 b and the solder that has flowed in may define and function as thesecond through conductive portion 43 b.

The distance x1 in the length direction L from the outer surface on theside of the first end surface Ca of the first external electrode 3 a tothe inner wall of the first through hole 46 a is preferably within about0.15 mm, and the distance x2 in the length direction L from the outersurface on the side of the second end surface Cb of the second outerelectrode 3 b to the inner wall of the second through hole 46 b ispreferably within about 0.15 mm, for example.

It should be noted that the stacking direction T of the internalelectrode layers 15 provided in the multilayer body 2 is perpendicularor substantially perpendicular to the first surface 4 a of theinterposer 4.

Method of Manufacturing Multilayer Ceramic Capacitor

FIG. 7 is a flowchart for explaining a non-limiting example of a methodof manufacturing the multilayer ceramic capacitor 1. FIG. 8 is aschematic plan view of a material sheet 103. FIG. 9 is a schematic viewshowing a stacked state of the material sheets 103. FIG. 10 is aschematic perspective view of a mother block 110.

Mother Block Manufacturing Step S1

First, a ceramic slurry including a ceramic powder, a binder and asolvent is prepared. The ceramic slurry is formed to be in a sheet shapeon a carrier film by using a die coater, gravure coater, micro gravurecoater, or the like, thus manufacturing a multilayer ceramic green sheet101.

Subsequently, the conductive paste is printed onto the multilayerceramic green sheet 101 by screen printing, ink jet printing, gravureprinting or the like, so as to have a strip-shaped pattern, thus forminga conductive pattern 102.

Thus, as shown in FIG. 8, the material sheet 103 is provided in whichthe conductive pattern 102 defining and functioning as the internalelectrode layer 15 is printed on the surface of the multilayer ceramicgreen sheet 101 defining and functioning as the dielectric layer 14.

Subsequently, as shown in FIG. 9, a plurality of material sheets 103 arestacked. More specifically, the plurality of material sheets 103 arestacked such that the strip-shaped conductive patterns 102 are directedin the same direction, and the strip-shaped conductive patterns 102 areshifted by half a pitch in the width direction between the adjacentmaterial sheets 103. Furthermore, an upper outer layer portion ceramicgreen sheet 112 defining and functioning as the upper outer layerportion 12 a is stacked on one side of the plurality of stacked materialsheet 103, while a lower outer layer portion ceramic green sheet 113defining and functioning as the lower outer layer portion 12 b isstacked on the other side thereof.

Subsequently, the upper outer layer portion ceramic green sheet 112, theplurality of stacked material sheets 103, and the lower outer layerportion ceramic green sheet 113 are subjected to thermo compressionbonding. As a result, the mother block 110 shown in FIG. 10 is formed.

Mother Block Dividing Step S2

Next, as shown in FIG. 10, the mother block 110 is divided along acutting line X and a cutting line Y intersecting the cutting line Xcorresponding to the dimension of the multilayer main body 10. As aresult, a plurality of multilayer main body 10 shown in FIG. 5 aremanufactured. It should be noted that, in the present preferredembodiment, the cutting line Y is orthogonal to the cutting line X.

Side Gap Portion Ceramic Green Sheet Affixing Step S3

Next, a ceramic slurry in which Mg is added as a sintering aid to thesame dielectric powder as that of the multilayer ceramic green sheet 101is produced. Then, a ceramic slurry is applied on the resin film, anddried to produce a side gap portion ceramic green sheet.

Then, by affixing the side gap portion ceramic green sheet on the sideportion where the internal electrode layer 15 of the multilayer mainbody 10 is exposed, the layer is formed as the side gap portion 30. Atthis time, the side gap ceramic green sheet is pressed against the sideportion where the internal electrode layer 15 of the multilayer mainbody 10 is exposed.

Side Gap Portion Firing Step S4

The multilayer main body 10 on which the layer which becomes the sidegap portion 30 is provided is subjected to degreasing treatment in anitrogen atmosphere under a predetermined condition, then fired at apredetermined temperature in a nitrogen-hydrogen-steam mixed atmosphere,and sintered to thus include the multilayer body 2.

Here, Mg of the side gap portion 30 migrates to the side of the internalelectrode layer 15 during sintering. Thus, after sintering, Mg in theside gap portion 30 is segregated on the side of the internal electrodelayer. Furthermore, the dielectric layer 14 and the side gap portion 30are made of substantially the same material; however, since the side gapportion 30 is affixed to the multilayer main body 10 including thedielectric layer 14, the interface is present between the side gapportion 30 and the multilayer main body 10 even after sintering.

External Electrode Forming Step S5

Next, at both ends of the multilayer body 2, the foundation electrodelayer 31, the conductive resin layer 32, and the plated layer 33 aresequentially formed to provide the external electrode 3.

Firing Step S6

Then, at a set firing temperature, heating for a predetermined time in anitrogen atmosphere is performed. Thus, the external electrode 3 isfired on the multilayer body 2 to manufacture the capacitor main body1A.

Interposer Preparing Step S7

The first through hole 46 a and the second through hole 46 b are formedin the rectangular plate material to penetrate the plate material, thusmanufacturing the interposer main body 40. Then, on one side of thelength direction L of the interposer main body 40, the first joiningelectrode 41 a is formed on the first surface 4 a and the first mountingelectrode 42 a is formed on the second surface 4 b, and the first metalfilm as the first through conductive portion 43 a is formed on the innerwall of the first through hole 46 a. On the other side of the lengthdirection L thereof, the second joining electrode 41 b is formed on thefirst surface 4 a, the second mounting electrode 42 b is formed on thesecond surface 4 b, and the second metal film as the second throughconductive portion 43 b is formed on the inner wall of the secondthrough hole 46 b.

Interposer Mounting Step S8

Then, the first surface 4 a of the interposer main body 40 is affixed tothe surface of the second main surface Ab of the capacitor main body 1A.

At this time, the first joining electrode 41 a of the interposer 4 andthe first external electrode 3 a of the capacitor main body 1A areconnected by the first conductive joining agent 44 a, which is solderfor joining, for example. The second joining electrode 41 b of theinterposer 4 and the second external electrode 3 b of the capacitor mainbody 1A are connected by the second conductive joining agent 44 b, whichis solder for joining, for example.

Thus, the multilayer ceramic capacitor 1 shown in FIG. 1 ismanufactured.

It should be noted that the multilayer ceramic capacitor 1 is mounted onthe substrate 200 thereafter. At this time, the first mounting electrode42 a of the interposer 4 is joined to a first substrate electrode 200 aprovided on the substrate 200 with a first conductive mounting agent 201a, which is solder for mounting, for example. The second mountingelectrode 42 b is joined to a second substrate electrode 200 b providedon the substrate 200 by a second conductive mounting agent 201 b, whichis solder for mounting, for example.

Thus, the multilayer ceramic capacitor 1 is mounted on the substrate200. Then, electrical conduction is provided among the first externalelectrode 3 a, the first conductive joining agent 44 a, the firstjoining electrode 41 a, the first through conductive portion 43 a, thefirst mounting electrode 42 a, and the first substrate electrode 200 a.Furthermore, electrical conduction is also provided among the secondexternal electrode 3 b, the second conductive joining agent 44 b, thesecond joining electrode 41 b, the second through conductive portion 43b, the second mounting electrode 42 b, and the second substrateelectrode 200 b.

Effects of the First Preferred Embodiment

The first preferred embodiment achieves the following effects.

In a multilayer ceramic capacitor, when the distance between theexternal electrode and the through conductive portion increases, thedistance from the external electrode to the mounting electrode providedon the side of the substrate also increases. This can result in higherequivalent series inductance (ESL) and more loss relative to highfrequency signals.

However, in the multilayer ceramic capacitor 1 of the first preferredembodiment, the first joining region 45 a extends directly above the endPa at the upper end of the first through conductive portion 43 a on theside of the first external electrode 3 a, and further extends beyond thefirst through hole 46 a and over the entire region directly above thefirst through hole 46 a.

The second joining region 45 b is a joining region of the secondexternal electrode 3 b and the second conductive joining agent 44, andextends directly above the end Pb at the upper end of the second throughconductive portion 43 b on the side of the second external electrode 3b, and further extends beyond the second through hole 46 b and over theentire region directly above the second through hole 46 b.

Therefore, when electricity flows through the first conductive joiningagent 44 a from the first external electrode 3 a to the first throughconductive portion 43 a, the electricity can flow through the shortestroute in the first conductive joining agent 44 a.

When electricity flows through the second conductive joining agent 44 bfrom the second external electrode 3 b to the second through conductiveportion 43 b, the electricity can flow through the shortest route in thesecond conductive joining agent 44 b.

Therefore, according to the first preferred embodiment, it is possibleto provide the multilayer ceramic capacitor 1 capable of reducing ESL.

Furthermore, it is possible to shorten the distance which electricityflows in the first external electrode 3 a by setting the distance x1 inthe length direction L from the outer surface on the first end surfaceCa of the first external electrode 3 a to the inner wall of the firstthrough hole 46 a within about 0.15 mm, for example, such that it ispossible to further reduce ESL.

Similarly, it is possible to shorten the distance which electricityflows in the second external electrode 3 b by setting the distance inthe length direction L from the outer surface on the second end surfaceCb of the second external electrode 3 b to the inner wall of the secondthrough hole 46 b within about 0.15 mm, for example, such that it ispossible to further reduce ESL.

Therefore, it is possible to provide the multilayer ceramic capacitor 1capable of reducing ESL.

Second Preferred Embodiment

Next, a multilayer ceramic capacitor 1 according to a second preferredembodiment of the present invention will be described.

FIGS. 11A and 11B provide partially enlarged views of a multilayerceramic capacitor 1 in a second preferred embodiment in which FIG. 11Ais an enlarged view on the left side in the length direction L shown inFIG. 2, and FIG. 11B is an enlarged view on the right side in the lengthdirection L.

The portions similar to those of the first preferred embodiment aredenoted by the same reference numerals, and a description thereof isomitted.

The characteristic portions of the second preferred embodiment are asfollows.

A first uncovered portion 47 a which is not covered with the first metalfilm as the first through conductive portion 43 a is provided on theside of the first surface 4 a of the inner wall of the first throughhole 46 a. It should be noted that, in the following description, thefirst metal film is also denoted by reference numeral 43 a.

A second uncovered portion 47 b which is not covered with the secondmetal film as the second through conductive portion 43 b is provided onthe side of the first surface 4 a of the inner wall of the secondthrough hole 46 b. It should be noted that, in the followingdescription, the second metal film is also denoted by reference numeral43 b.

The first metal film 43 a is provided on the inner wall of the firstthrough hole 46 a on one side in the length direction L on which thefirst external electrode 3 a is provided, and the first uncoveredportion 47 a is provided on the other side in the length direction L.

The second metal film 43 b is provided on the inner wall of the secondthrough hole 46 b on the other side in the length direction L on whichthe second external electrode 3 b is provided, and the second uncoveredportion 47 b is provided on the one side of the length direction L.

Effects of the Second Preferred Embodiment

The second preferred embodiment achieves the following effects.

As described in the first preferred embodiment, in the interposeraffixing step S8, the interposer 4 and the capacitor main body 1A arejoined by the first conductive joining agent 44 a, which is solder forjoining, joining the first external electrode 3 a and the first joiningelectrode 41 a, and by the second conductive joining agent 44 b, whichis solder for joining, joining the second external electrode 3 b and thesecond joining electrode 41 b.

Here, the first conductive joining agent 44 a and the second conductivejoining agent 44 b have higher wettability with respect to the firstmetal film 43 a and the second metal film 43 b than the first uncoveredportion 47 a and the second uncovered portion 47 b.

Therefore, when the first conductive joining agent 44 a is heated andmelted at the time of joining, the first conductive joining agent 44 aflows into the first through hole 46 a along the first metal film 43 ahaving high wettability. However, the first conductive joining agent 44a does not flow into the first uncovered portion 47 a having lowwettability. Therefore, the interior of the first through hole 46 a isnot completely filled with the first conductive joining agent 44 a.

Furthermore, when the second conductive joining agent 44 b is heated andmelted at the time of joining, the second conductive joining agent 44 bflows into the second through hole 46 b along the second metal film 43 bhaving high wettability. However, the second conductive joining agent 44b does not flow into the second uncovered portion 47 b having lowwettability. Therefore, the interior of the second through hole 46 b isnot completely filled with the second conductive joining agent 44 b.

In such a way, a gap is provided in each of the first through hole 46 aand the second through hole 46 b, and the gap can be easily providedwithout performing a step of, for example, covering the upper portion ofthe first through hole 46 a or the second through hole 46 b.

Furthermore, in a case in which the first through hole 46 a and thesecond through hole 46 b are respectively filled with the firstconductive joining agent 44 a and the second conductive joining agent 44b when the multilayer ceramic capacitor 1 is mounted on the substrate200, the first conductive mounting agent 201 a and the second conductivemounting agent 201 b, each of which is solder for mounting, cannot enterthe first through hole 46 a and the second through hole 46 b, and thus,the posture at the time of mounting is not stabilized.

However, in the present preferred embodiment, the interior of the firstthrough hole 46 a or the second through hole 46 b is not completelyfilled with the first conductive joining agent 44 a or the secondconductive joining agent 44 b. Therefore, when the multilayer ceramiccapacitor 1 is mounted on the substrate 200 by the first conductivemounting agent 201 a and the second conductive mounting agent 201 b, thefirst conductive mounting agent 201 a and the second conductive mountingagent 201 b can enter the first through hole 46 a and the second throughhole 46 b, and the posture at the time of mounting is stabilized.

Furthermore, as can be seen from the cross-section shown in FIGS. 11Aand 11B, the first conductive joining agent 44 a and the secondconductive joining agent 44 b are present at the upper portions of thefirst through hole 46 a and the second through hole 46 b. However, atthe upper portions of the first through hole 46 a and the second throughhole 46 b, there is a portion in which the first conductive joiningagent 44 a or the second conductive joining agent 44 b is not present ina portion other than the cross section shown in FIGS. 11A and 11B.

Therefore, an air hole (not shown) leading from the second surface 4 bto the first surface 4 a is present in the first through hole 46 a andthe second through hole 46 b. The air hole is a hole through which aircan pass. Therefore, when the multilayer ceramic capacitor 1 is mountedon the substrate 200, air between the first conductive mounting agent201 a and the second conductive mounting agent 201 b, and the multilayerceramic capacitor 1 can pass through a portion (i.e., an air hole) ofeach of the first through hole 46 a and the second through hole 46 bwhich is not filled with the first conductive joining agent 44 a or thesecond conductive joining agent 44 b, and escape to the side of thefirst surface 4 a of the interposer 4.

Therefore, allowing the air to escape as above also stabilizes theposture when the multilayer ceramic capacitor 1 is mounted on thesubstrate 200 with the first conductive mounting agent 201 a and thesecond conductive mounting agent 201 b.

On the other hand, in a case in which the first conductive joining agent44 a and the second conductive joining agent 44 b do not flow at all tothe first through hole 46 a and the second through hole 46 b at the timeof joining the capacitor main body 1A and the interposer 4, the joiningforce between the capacitor main body 1A and the interposer 4 isweakened.

However, in the second preferred embodiment, the first conductivejoining agent 44 a and the second conductive joining agent 44 bpartially flow into the first through hole 46 a and the second throughhole 46 b along the first metal film 43 a and the second metal film 43b. Therefore, strong joining between the capacitor main body 1A and theinterposer 4 is ensured.

Modification

FIGS. 12A and 12B provide partially enlarged views of the multilayerceramic capacitor in a modification of the second preferred embodimentin which FIG. 12A is one portion in the length direction, and FIG. 12Bis the other portion in the length direction. FIG. 13 is a view of themultilayer ceramic capacitor of the modification of the second preferredembodiment seen from a side of the second surface 4 b.

The modification of the multilayer ceramic capacitor 1 of the secondpreferred embodiment is different from the above-described preferredembodiment in that the first metal film 43 a is provided on the otherside in the length direction L of the inner wall of the first throughhole 46 a and the first uncovered portion 47 a is provided on the oneside in the length direction L of the inner wall of the first throughhole 46 a, and the second metal film 43 b is provided on the other sidein the length direction L of the inner wall of the second through hole46 b and the second uncovered portion 47 b is provided on the one sidein the length direction L of the inner wall of the second through hole46 b.

As shown in FIG. 13, in the modification, the first metal film 43 aprovided on the other side of the first through hole 46 a is connectedto the first mounting electrode 42 a by the first mounting electrode 42a extending to the other side of the first through hole 46 a on the sideof the second surface 4 b. The same applies to the connection betweenthe first metal film 43 a and the first joining electrode 41 a on theside of the first surface 4 a.

The second metal film 43 b provided on the one side of the secondthrough holes 46 b is connected to the second mounting electrode 42 b bythe second mounting electrode 42 b extending to the other side of thesecond through hole 46 b on the side of the second surface 4 b. The sameapplies to the connection between the second metal film 43 b and thesecond joining electrode 41 b on the side of the first surface 4 a.Since the rest is the same as that of the above-described secondpreferred embodiment, description thereof is omitted.

The modification of the second preferred embodiment also achieves thesame effects as the above-described second preferred embodiment.

Third Preferred Embodiment

Next, a multilayer ceramic capacitor 1 according to a third preferredembodiment of the present invention will be described.

FIGS. 14A and 14B provide partially enlarged views of a state in which amultilayer ceramic capacitor of a third preferred embodiment is mountedon the substrate 200 in which FIG. 14A is an enlarged view on the leftside in the length direction L, and FIG. 14B is an enlarged view on theright side in the length direction L.

The portions similar to those of the first preferred embodiment aredenoted by the same reference numerals, and descriptions thereof areomitted.

The characteristic portions of the third preferred embodiment are asfollows.

The first mounting electrode 42 a includes a first portion 49 a coveringthe lower portion of a first interposer end surface 48 a on one side inthe length direction L of the interposer 4, and the second mountingelectrode 42 b includes a second portion 49 b covering the lower portionof a second interposer end surface 48 b on the other side in the lengthdirection L of the interposer 4.

The length ta of the first portion 49 a in the stacking direction T ispreferably less than half the thickness of the interposer 4, and thelength tb of the second portion 49 b in the stacking direction T ispreferably less than half the thickness of the interposer 4.

For example, in a case in which the thickness of the interposer 4 isabout 1.0 mm or less, the length ta of the first portion 49 a in thestacking direction T is preferably about 0.3 mm or less, and the lengthtb of the second portion 49 b in the stacking direction T is preferablyabout 0.3 mm or less.

In a case in which the thickness of the interposer 4 is about 0.5 mm orless, the length ta of the first portion 49 a in the stacking directionT is preferably about 0.16 mm or less, and the length tb of the secondportion 49 b in the stacking direction T is preferably about 0.16 mm orless, for example.

In a case in which the thickness of the interposer 4 is about 0.2 mm orless, the length ta of the first portion 49 a in the stacking directionT is preferably about 0.06 mm or less, and the length tb of the secondportion 49 b in the stacking direction T is preferably about 0.06 mm orless, for example.

In a case in which the thickness of the interposer 4 is about 0.1 mm orless, the length ta of the first portion 49 a in the stacking directionT is preferably about 0.03 mm or less, and the length tb of the secondportion 49 b in the stacking direction T is preferably about 0.03 mm orless, for example.

Effects of the Third Preferred Embodiment

The third preferred embodiment achieves the following effects.

When the multilayer ceramic capacitor 1 is joined to the substrate 200,the first conductive mounting agent 201 a, which is solder for mounting,for example, is provided on the first substrate electrode 200 a providedon the substrate 200, and the second conductive mounting agent 201 b,which is solder for mounting, for example, is provided on the secondsubstrate electrode 200 b provided on the substrate 200.

Then, the first conductive mounting agent 201 a and the secondconductive mounting agent 201 b are melted by heating the substrate 200.

The multilayer ceramic capacitor 1 is mounted such that the interposer 4is provided on the substrate 200 in a state in which the firstconductive mounting agent 201 a and the second conductive mounting agent201 b are melted so that the first mounting electrode 42 a is above thefirst conductive mounting agent 201 a and the second mounting electrode42 b is above the second conductive mounting agent 201 b.

Here, the first mounting electrode 42 a includes the first portion 49 acovering the lower portion of the first interposer end surface 48 a.Therefore, as shown in FIGS. 14A and 14B, the first conductive mountingagent 201 a extends around the first portion 49 a of the firstinterposer end surface 48 a at the time of mounting.

On the other hand, the second mounting electrode 42 b includes thesecond portion 49 b covering the lower portion of the second interposerend surface 48 b. Therefore, as shown in FIGS. 14A and 14B, the secondconductive mounting agent 201 b extends around the second portion 49 bof the second interposer end surface 48 b at the time of mounting.

As a result, in the interposer 4, the first interposer end surface 48 aand the second interposer end surface 48 b, which are both end surfacesin the length direction L, are pulled from both ends by the surfacetension of the first conductive mounting agent 201 a and the surfacetension of the second conductive mounting agent 201 b. Therefore, theinterposer 4, i.e., the multilayer ceramic capacitor 1, is aligned inthe length direction L, and thus, it is possible to stabilize theposture at the time of mounting.

Fourth Preferred Embodiment

Next, a multilayer ceramic capacitor 1 according to a fourth preferredembodiment of the present invention will be described.

FIGS. 15A and 15B provide partially enlarged views of a multilayerceramic capacitor 1 of a fourth preferred embodiment in which FIG. 15Ais an enlarged view on the left side in the length direction L, and FIG.15B is an enlarged view on the right side in the length direction L.

The portions similar to those of the first preferred embodiment and thethird preferred embodiment are denoted by the same reference numerals,and descriptions thereof are omitted.

The characteristic portions of the fourth preferred embodiment are asfollows.

The first joining electrode 41 a includes a first portion 50 a coveringthe upper portion of the first interposer end surface 48 a on one sidein the length direction L of the interposer 4, and the second joiningelectrode 41 b has a second portion 50 b covering the upper portion ofthe second interposer end surface 48 b on the other side in the lengthdirection L of the interposer 4.

The length s1 of the first portion 50 a in the stacking direction T ispreferably less than half the thickness of the interposer 4, and thelength s2 of the second portion 50 b in the stacking direction T ispreferably less than half the thickness of the interposer 4.

For example, in a case in which the thickness of the interposer 4 isabout 1.0 mm or less, the length s1 in the stacking direction T of thefirst portion 50 a is preferably about 0.3 mm or less, and the length s2in the stacking direction T of the second portion 50 b is preferablyabout 0.3 mm or less, for example.

In a case in which the thickness of the interposer 4 is about 0.5 mm orless, the length s1 of the first portion 50 a in the stacking directionT is preferably about 0.16 mm or less, and the length s2 of the secondportion 50 b in the stacking direction T is preferably about 0.16 mm orless, for example.

In a case in which the thickness of the interposer 4 is about 0.2 mm orless, the length s1 of the first portion 50 a in the stacking directionT is preferably about 0.06 mm or less, and the length s2 of the secondportion 50 b in the stacking direction T is preferably about 0.06 mm orless, for example.

In a case in which the thickness of the interposer 4 is about 0.1 mm orless, the length s1 of the first portion 50 a in the stacking directionT is preferably about 0.03 mm or less, and the length s2 of the secondportion 50 b in the stacking direction T is preferably about 0.03 mm orless, for example.

Effects of the Fourth Preferred Embodiment

The fourth preferred embodiment achieves the following effects.

When the interposer 4 is joined to the capacitor main body 1A, the firstconductive joining agent 44 a, which is solder for joining, is providedon the first joining electrode 41 a provided on the interposer 4, forexample, and the second conductive joining agent 44 b, which is solderfor joining, is provided on the second joining electrode 41 b providedon the interposer 4, for example.

Then, the first conductive joining agent 44 a and the second conductivejoining agent 44 b are melted by heating the interposer 4.

The capacitor main body 1A is joined on the interposer such that thecapacitor main body 1A is provided on the interposer 4 in a state wherethe first conductive joining agent 44 a and the second conductivejoining agent 44 b are melted, so that the first external electrode 3 ais on the first conductive joining agent 44 a, and the second externalelectrode 3 b is on the second conductive joining agent 44 b.

Here, the first joining electrode 41 a includes the first portion 50 acovering the upper portion of the first interposer end surface 48 a.Therefore, at the time of joining as shown in FIGS. 15A and 15B, thefirst conductive joining agent 44 a extends around the first portion 50a of the first interposer end surface 48 a.

The second joining electrode 41 b includes the second portion 50 bcovering the upper portion of the second interposer end surface 48 b.Therefore, at the time of joining as shown in FIGS. 15A and 15B, thesecond conductive joining agent 44 b extends around the second portion50 b of the second interposer end surface 48 b.

As a result, in the interposer 4, the first interposer end surface 48 aand the second interposer end surface 48 b, which are both end surfacesin the length direction L, are pulled from both ends by the surfacetension of the first conductive joining agent 44 a and the surfacetension of the second conductive joining agent 44 b. Therefore, theinterposer 4 is aligned in the length direction L, and thus, it ispossible to stabilize the posture with respect to the capacitor mainbody 1A.

Furthermore, in a case in which the first joining electrode 41 a doesnot extend to the lower portion of the first interposer end surface 48a, the first conductive mounting agent 201 a does not reach the firstinterposer end surface 48 a when the multilayer ceramic capacitor 1 ismounted on the substrate 200. Therefore, it is difficult to form aso-called fillet in which the first conductive mounting agent 201 a israised.

Likewise, in a case in which the second joining electrode 41 b does notextend to the lower portion of the second interposer end surface 48 b,the second conductive mounting agent 201 b does not reach the secondinterposer end surface 48 b when the multilayer ceramic capacitor 1 ismounted on the substrate 200. Therefore, it is difficult to form aso-called fillet in which the second conductive mounting agent 201 b israised.

Fifth Preferred Embodiment

Next, a multilayer ceramic capacitor 1 according to a fifth preferredembodiment of the present invention will be described.

FIGS. 16A and 16B are partially enlarged views of a multilayer ceramiccapacitor 1 of a fifth preferred embodiment in which FIG. 16A is anenlarged view on the left side in the length direction L, and FIG. 16Bis an enlarged view on the right side in the length direction L.

The portions similar to those of the first preferred embodiment aredenoted by the same reference numerals, and a description thereof isomitted.

The characteristic portions of the fifth preferred embodiment are asfollows.

The inner wall of the first through hole 46 a is covered with the firstmetal film 43 a, the side of the first surface 4 a of the first throughhole 46 a is filled with the first conductive joining agent 44 a, whichis, for example, solder for joining, and the first conductive joiningagent 44 a includes a portion having a center which is recessed in amortar shape when the first through hole 46 a is viewed from the secondsurface 4 b toward the side of the first surface 4 a.

The inner wall of the second through hole 46 b is covered with thesecond metal film 43 b, the side of the first surface 4 a of the secondthrough hole 46 b is filled with the second conductive joining agent 44b, which is, for example, solder for joining, and the second conductivejoining agent 44 b includes a portion having a center which is recessedin a mortar shape when the second through hole 46 b is viewed from thesecond surface 4 b toward the side of the first surface 4 a.

Furthermore, an edge 51 a of the first conductive joining agent 44 aflowing into the first through hole 46 a on the inner wall of the firstthrough hole 46 a is preferably located closer to the side of the firstsurface 4 a than the half of the thickness of the interposer 4.Furthermore, the edge 51 a is more preferably located closer to the sideof the first surface 4 a than one third of the thickness of theinterposer 4.

An edge 51 b of the second conductive joining agent 44 b flowing intothe second through hole 46 b on the inner wall of the second throughhole 46 b is preferably located closer to the side of the first surface4 a than the half of the thickness of the interposer 4. Furthermore, theedge 51 b is more preferably located closer to the side of the firstsurface 4 a than one third of the thickness of the interposer 4.

It should be noted that the thickness of the interposer 4 is, forexample, about 1.0 mm or less, about 0.5 mm or less, about 0.2 mm orless, or about 0.1 mm or less.

In the fifth preferred embodiment, in order for the portion having thecenter in each of the first conductive joining agent 44 a and the secondconductive joining agent 44 b to be recessed when viewed from the secondsurface 4 b toward the side of the first surface 4 a, the interposeraffixing step S8 is performed as follows, for example. However, thepresent invention is not limited thereto, and may be done by anothermethod.

First, the first conductive joining agent 44 a and the second conductivejoining agent 44 b, which are each solder for joining, for example, areprovided on the first joining electrode 41 a and the second joiningelectrode 41 b. At this time, the first conductive joining agent 44 aand the second conductive joining agent 44 b are provided on the upperportions of the first through holes 46 a and the second through holes 46b, respectively, in a larger amount than the other portions.

It should be noted that wettability of the first conductive joiningagent 44 a with respect to the first metal film 43 a, and wettability ofthe second conductive joining agent 44 b with respect to the secondmetal film 43 b are preferably increased by providing a thin solder filmin advance on the surfaces of the first metal film 43 a of the innerwall of the first through hole 46 a and the second metal film 43 b ofthe inner wall of the second through hole 46 b, or performing othersurface processing.

Then, the first conductive joining agent 44 a and the second conductivejoining agent 44 b are melted by heating the interposer 4.

At this time, since the first conductive joining agent 44 a and thesecond conductive joining agent 44 b are provided in a larger amount onthe upper portion of the first through hole 46 a and the second throughhole 46 b than the other portions, the first conductive joining agent 44a and the second conductive joining agent 44 b flow onto the sides ofthe first mounting electrode 42 a and the second mounting electrode 42 bbelow, along the surfaces of the first metal film 43 a and the secondmetal film 43 b.

Here, the heating time and temperature are adjusted so that the firstconductive joining agent 44 a and the second conductive joining agent 44b respectively flow out to the side of the first mounting electrode 42 aand to the side of the second mounting electrode 42 b below, but do notcompletely fill the first through hole 46 a and the second through hole46 b, and the portion having the center in each of the first conductivejoining agent 44 a and the second conductive joining agent 44 b isrecessed when viewed from the second surface 4 b toward the side of thefirst surface 4 a.

The capacitor main body 1A is joined on the interposer such that thecapacitor main body 1A is provided on the interposer 4 in a state wherethe first conductive joining agent 44 a and the second conductivejoining agent 44 b are melted, so that the first external electrode 3 ais on the first conductive joining agent 44 a, and the second externalelectrode 3 b is on the second conductive joining agent 44 b.

In this way, the portion having the center of each of the firstconductive joining agent 44 a and the second conductive joining agent 44b is provided so as to appear recessed when viewed from the secondsurface 4 b to the side of the first surface 4 a.

Effects of the Fifth Preferred Embodiment

According to the fifth preferred embodiment, a gap is provided in eachof the first through hole 46 a and the second through hole 46 b, and thegap can be easily provided without performing a step of, for example,covering the upper portion of the first through hole 46 a or the secondthrough hole 46 b.

Furthermore, when the multilayer ceramic capacitor 1 is mounted on thesubstrate 200, the first mounting electrode 42 a of the interposer 4 isjoined to the first substrate electrode 200 a provided on the substrate200 with, for example, the first conductive mounting agent 201 a, whichis solder for mounting. The second mounting electrode 42 b is joined tothe second substrate electrode 200 b provided on the substrate 200, forexample, by the second conductive mounting agent 201 b, which is solderfor mounting.

Here, in the fifth preferred embodiment, the first conductive joiningagent 44 a is present on the upper portion of the first through hole 46a, and the portion having a center of the first conductive joining agent44 a is recessed in a mortar shape, for example, when the first throughhole 46 a is viewed from the second surface 4 b to the side of the firstsurface 4 a.

The second conductive joining agent 44 b is present on the upper portionof the second through hole 46 b, and the portion having a center of thesecond conductive joining agent 44 b is recessed in a mortar shape, forexample, when the second through hole 46 b is viewed from the secondsurface 4 b to the side of the first surface 4 a.

That is, the interiors of the first through hole 46 a and the secondthrough hole 46 b are not completely filled with the first conductivejoining agent 44 a and the second conductive joining agent 44 b,respectively, and thus gaps are provided. Therefore, when the multilayerceramic capacitor 1 is mounted on the substrate 200 by the firstconductive mounting agent 201 a and the second conductive mounting agent201 b, it is possible for the first conductive mounting agent 201 a andthe second conductive mounting agent 201 b to enter the gap between thefirst through hole 46 a and the second through hole 46 b, and theposture at the time of mounting is stabilized.

Furthermore, the surface on the side of the second surface 4 b in thefirst through hole 46 a of the first conductive joining agent 44 aincludes the portion having the recessed center, and thus includes alarger area than when the center is flat. The surface on the side of thesecond surface 4 b in the second through hole 46 b of the secondconductive joining agent 44 b includes the portion having the recessedcenter, and thus includes a larger area than when the center is flat.

Therefore, since the contact area between the first conductive mountingagent 201 a and the second conductive mounting agent 201 b, and thefirst conductive joining agent 44 a and the second conductive joiningagent 44 b becomes large, the joining force between the first conductivemounting agent 201 a and the second conductive mounting agent 201 b, andthe first conductive joining agent 44 a and the second conductivejoining agent 44 b can be increased.

Although the first preferred embodiment to the fifth preferredembodiment of the present invention have been described above, thepresent invention is not intended to be limited to the preferredembodiments, and various modifications can be made within the scope ofthe gist thereof.

For example, in the above-described preferred embodiment shown in FIG.3, in the width direction W, the interposer 4 is substantially the samesize as the outer electrode 3 in the width direction W; however, thepresent invention is not limited thereto. That is, in the widthdirection W, the interposer 4 may be smaller than the outer electrode 3in the width direction W. For example, in the width direction W, theinterposer 4 may be narrower than the widest portion of the internalelectrode layer 15 in the width direction W by, for example, about 10μm.

Furthermore, a description is provided of a preferred embodiment with aconfiguration in which one interposer 4 is affixed to the capacitor mainbody 1A; however, the present invention is not limited thereto. Forexample, the interposer 4 may be configured as a two-way dividinginterposer, for example, including a first interposer portion includinga joining electrode connected to the first external electrode 3 a, and asecond interposer portion that is spaced apart from the first interposerportion and includes a joining electrode connected to the secondexternal electrode 3 b.

While preferred embodiments of the present invention have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present invention. The scope of the present invention,therefore, is to be determined solely by the following claims.

What is claimed is:
 1. A multilayer ceramic capacitor comprising: acapacitor main body; and an interposer; the capacitor main bodyincluding: a multilayer body including dielectric layers and internalelectrode layers alternately stacked, a first main surface on one sideand a second main surface on the other side in a stacking direction, anda first end surface on one side and a second end surface on the otherside in a length direction intersecting the stacking direction; a firstexternal electrode provided on the first end surface of the multilayerbody and extending from the first end surface to a portion of the firstmain surface and a portion of the second main surface; and a secondexternal electrode provided on the second end surface of the multilayerbody and extending from the second end surface to a portion of the firstmain surface and a portion of the second main surface; the interposerbeing at or adjacent to the second main surface of the capacitor mainbody, and including a first surface facing the second main surface, anda second surface opposite to the first surface; wherein the interposerincludes, on a side of the first external electrode in the lengthdirection: a first joining electrode on the first surface; a firstmounting electrode on the second surface; and a first through hole thatpenetrates the interposer in the stacking direction, and provideselectrical conduction between the first joining electrode and the firstmounting electrode, the first through hole further including a firstmetal film provided on an inner wall thereof; and the interposerincludes, on a side of the second external electrode in the lengthdirection: a second joining electrode on the first surface; a secondmounting electrode on the second surface; a second through hole thatpenetrates the interposer in the stacking direction, and provideselectrical conduction between the second joining electrode and thesecond mounting electrode, the second through hole further including asecond metal film provided on an inner wall thereof; a first uncoveredportion is provided, which is not covered by the first metal film, onthe first surface of the inner wall of the first through hole; and asecond uncovered portion is provided, which is not covered by the secondmetal film, on the first surface of the inner wall of the second throughhole.
 2. The multilayer ceramic capacitor according to claim 1, whereinon the inner wall of the first through hole, the first metal film isprovided on the one side in the length direction, and the firstuncovered portion is provided on the other side in the length direction;and on the inner wall of the second through hole, the second metal filmis provided on the other side in the length direction, and the seconduncovered portion is provided on the one side in the length direction.3. The multilayer ceramic capacitor according to claim 1, wherein on theinner wall of the first through hole, the first metal film is providedon the other side in the length direction, and the first uncoveredportion is provided on the one side in the length direction; and on theinner wall of the second through hole, the second metal film is providedon the one side in the length direction, and the second uncoveredportion is provided on the other side in the length direction.
 4. Themultilayer ceramic capacitor according to claim 1, wherein a distance inthe length direction from an outer surface of the first end surface ofthe first external electrode to the inner wall of the first through holeis within about 0.15 mm; and a distance in the length direction from anouter surface of the second end surface of the second external electrodeto the inner wall of the second through hole is within about 0.15 mm. 5.The multilayer ceramic capacitor according to claim 1, wherein astacking direction of the internal electrode layers in the multilayerbody is perpendicular or substantially perpendicular to the firstsurface of the interposer.
 6. The multilayer ceramic capacitor accordingto claim 1, wherein the capacitor main body has a substantiallyrectangular shape.
 7. The multilayer ceramic capacitor according toclaim 1, wherein the capacitor main body is rounded at a corner or aridge.
 8. The multilayer ceramic capacitor according to claim 1, whereinthe capacitor main body has a dimension in the length direction of about0.2 mm or more and about 10 mm or less, a dimension in the widthdirection of about 0.1 mm or more and about 10 mm or less, and adimension in the stacking direction of about 0.1 mm or more and about 5mm or less.
 9. The multilayer ceramic capacitor according to claim 1,wherein the capacitor main body includes a side gap portion.
 10. Themultilayer ceramic capacitor according to claim 9, wherein the side gapportion includes an outer side gap layer and an inner side gap layer.11. The multilayer ceramic capacitor according to claim 10, wherein theouter side gap layer has a content of Si greater than that of the innerside gap layer.
 12. The multilayer ceramic capacitor according to claim1, wherein the interposer is a single plate including resin.
 13. Themultilayer ceramic capacitor according to claim 1, further comprising: afirst joining region that joins the first external electrode and a firstconductive joining agent extends directly above an end at an upper endof a first through conductive portion on the side of the first externalelectrode; and a second joining region that joins the second externalelectrode and a second conductive joining agent extends directly abovean end at an upper end of a second through conductive portion on theside of the second external electrode.
 14. The multilayer ceramiccapacitor according to claim 13, wherein the interposer and thecapacitor main body are joined by the first conductive joining agent andby the second conductive joining agent.
 15. The multilayer ceramiccapacitor according to claim 13, wherein each of the first conductivejoining agent and the second conductive joining agent include solder.16. The multilayer ceramic capacitor according to claim 13, wherein thefirst conductive joining agent and the second conductive joining agenthave higher wettability with respect to the first metal film and thesecond metal film than the first uncovered portion and the seconduncovered portion.
 17. The multilayer ceramic capacitor according toclaim 13, wherein the first through hole is not completely filled withthe first conductive joining agent.
 18. The multilayer ceramic capacitoraccording to claim 13, wherein the second through hole is not completelyfilled with the second conductive joining agent.
 19. The multilayerceramic capacitor according to claim 13, wherein the first conductivejoining agent and the second conductive joining agent are present atupper portions of the first through hole and the second through hole.20. The multilayer ceramic capacitor according to claim 13, wherein anair hole extends between the first through hole and the second throughhole.